Wireless user devices exchange wireless signals with wireless communication networks for data services like voice-calling and internet-access. The wireless communication networks have wireless access points that exchange the wireless signals with the wireless user devices. Popular forms of wireless networking comprise Long Term Evolution (LTE) and Fifth Generation New Radio (5GNR). LTE and 5GNR use Carrier Aggregation (CA) technology to dramatically increase the bandwidth and corresponding data speed for the wireless user devices.
Typically, a wireless access point serves a wireless user device over a single uplink and a single downlink. With CA, the wireless access point still serves the wireless user device over the single uplink but now serves the wireless user device over multiple downlinks. The uplink and one downlink comprise a CA primary component carrier. The remaining downlinks comprise CA secondary component carriers. With multi-band CA, the secondary component carriers may use different frequency bands from each other and from the primary component carrier. With LTE/5GNR dual connectivity, the primary component carrier uses LTE and the secondary component carriers may use LTE and/or 5GNR over the various secondary component carriers.
Modulation entails the physical mixing of signals on a common medium. For example, a one gigahertz carrier signal may be mixed with a ten kilohertz data signal. The modulation results include Nyquist components at various frequencies. Nyquist components are produced at the sum of the frequencies, the difference of between the frequencies, and their multiples. When the data frequency is much smaller than the carrier frequency, the Nyquist components are effectively multiples of the carrier frequency.
The wireless access points comprise antennas, circuitry, and data links that may generate Nyquist products due to rust, damage, or some other defect. The defect acts like a mixer and generates unwanted wireless signals at multiples of the carrier frequency. These unwanted wireless signals are referred to as intermodulation interference. Thus, antenna rust may generate intermodulation interference from the carrier frequency that destroys wireless signals at multiples of the carrier frequency.
With multi-band CA, the intermodulation interference generated from a component carrier can destroy the wireless signal quality of another component carrier. For example, the third order intermodulation interference generated from a one gigahertz component carrier can destroy the signal quality of a three gigahertz component carrier. Unfortunately, 5GNR/LTE access points do not efficiently and effectively mitigate intermodulation interference when using multi-band CA.